Hydraulic motor



Aug. 23, 193s.

f7. fazZ D. JOHNSTON HYDRAULIC MOTOR Fled May 8, 1937 4 Sheets-Sheet l ,477-0 RA/En'- Aug. 23, 1938. D. JOHNSTON 2,128,048

` HYDRAULIC MOTOR Filed MayS, 1937 4 Sheets-Sheet 2 Aug' 23,1938.

Filed May 8l 1937 D'. JOHNSTON 2,128,048

HYDRAULIC MOTOR T7-GRAIN( Aug. 23, 1938.

D. JOHNSTON HYDRAULIC MOTOR Filed May 8, 1937 4 Sheets-Sheet 4 PatentedrAug. 23, 1938 n. I v y UNITED sTATEs PATENT OFFICE Mo'ron.` I

Douglas Johnston, Greenwood, Miss. 3 1941 Application May 8', 1937, Serial No. 141,441 l 13 claims. (ci. 121-157) This invention relates to certain new and useful lscribed and set forth' in the appended claims, is improvements in a hydraulic motor in the form applicable, without change of the generic prinof a tramper for use, particularly, in packing Ciple involved, to many other kinds of devices; cotton, and has for its general object to provide I have in mind oil drilling machines, pneumatic a highly simplied device of this character which machines of various types, pumps, compressors, shall be positive and reliable in operation and pile drivers, forging hammers, and many other which shall use the minimum amount of oil, or types of machines, to any one of which my inother driving medium, and in operation shall vention may be applied, with or without suitable require neither a high degree of skill nor ex- Irwdlficationsl adapting it to a particular applitended previous experience for its ready and .-Cetion. but without depertlng from the prin- 10 successful use. 1 y ciple of the invention.

Owing to simplicity of construction, compact- I wish to state further, that while the present ness, and relative small size, my improved. form -of invention contemplates the use of oil, tramper may be manufactured at small cost as pleeed under preSSure'by a pump. 81S the driving gl s ,15 compared with other trampers now in use, and medium for operatingthe tramper, other mobile 15 A being, aside from the pressure pump and source mediums could be utilized for-this purpose inof iluid, entirely self-contained, it may be readily Clllding SaS, Steam, air and water. Wherever, irl transported from place to place without danger the following description and claims, the use of of breaking, or otherwise harming it, oil is referred to as the driving medium, it is to My improved tramper comprises a hollow be understood that such term is .employed as 20 piston-rod iixedly secured at its upper end in typical of various fluids or liquids which might an overhead support andhaving at its lower end be employed. and lS 110i? intended t0 exclude the a unitary enlargement provided with certain ports Se 0f Steam, gas. air, er in fact, any Other mbile and passages and constituting a stationary pisdriving medium which it might be foundcould Y ton, a oating sleeveprovided with cooperating be utilized as the driving medium for operating 25 ports and slidably mounted on said piston and the tramper, or any other device employing e piston-rod, and having for its purpose to act as reciprocating member. a valve. for automatically changing a iicw of oil Finally, it remains to be stated that in illusat each end of the stroke so as to reverse the trailing my invention I have omitted any showdirection of the ram case, or tramper proper, and ing of the press bOX into Which the Colli/0D is v30 keep it going continuously;l an outside floating packed by the tramper, or the lint slide and bat CaSe Carrying at its lower end the tramper foot, feeder commonly associated therewith, as these constituting the tramper proper, and slidably DartSdO rlOt irl enymem'ler interim-t0 the Opermounted o'nsaid sleeve and piston-md, and a, ationof the tramper and their use and appliiioati'ng plunger-valve for opening or lclosing cation are perfeetlyiWeU-knowrl t0 those Skilled 35 certain ports to release pressure in said sleeve in the art.

and case, or to permit the same to be built up, The invention is illustrated .in the accompanyand to prevent the escape of high pressure oil, ing drawings, in Whehf according to its position. Figure 1 is a vertical sectional view of the 40 Thus my device has but three moving parts. tramper assembled; .A 40 namely, the outer case, the sleeve and the Figure 2 is a sectional plan view taken on the plunger-valve, all of which are automatically line 2--2 of Figure l; operated, the sleeve and plunger-valve in part Figure 3 is a longitudinal sectional plan view by cil pressure and in part by contact therewith on an enlarged scale taken on the line 3-3 of of the outer ram ease, or a part carried thereby, Figure 6 through the piston and sleeve the lat- 45 and the ram case solely by oil pressure produced ter being in its uppermost positionand showing in the same above or below the sleeve, accorda portion of the ram case and of the hollow ing to the direction of movement to be imparted piston-rod; to said case and the tramper foot carried Figure 4 is a cross-sectional view taken on the thereby line 4 4 of Figure 3, viewed in the direction of 50 I have stated that my invention is intended the arrows; particularly for use in packing cotton. I am Figure 5 is a View similar to Figure 3 but taken aware that-,the principle of hydraulically operon the line 5-5 of Figure 6 and viewed in the ating a reciprocable member, suchas the ram direction of the arrows;

I l case, or tramper, of my invention, herein de- Figure 6 is a cross-sectional view taken on the 55 line 5 8 of Figure 5 and viewed in the direction of the arrows;

Figui-e7 is a central vertical sectional view on the same scale as Figure 3, taken on the line 1-1 of Figure 4 and viewed in the direction of the arrows;

Figure 8 is a cross-sectional view taken on the line 8-8 of Figure 'I and viewed .in the direction of the arrows;

Figures. 9, 10 and 11 are views corresponding, respectively, to Figures 3, 5 and 7, but Showing in each view the sleeve in its lowermost position; and

Figure 12 is a cross sectional view taken on the line I2-I2 of Figure 9 and viewed in the direction of the arrows.

Referring now to the drawings, the numeral I indicates a hollow piston-rod, which is flxedly secured at its upper end in a casting 2, into which it is screwed. At its lower end the piston-rod is secured into the upper end of a stationary piston 3. Slidably mounted on this piston is a sleeve 4 having a closedlower end 5. Piston rings 5 are interposed at intervals between piston v3 and sleeve 4. The numeral 1 indicates the ram case which is mounted to slide up and down on thepiston-rod I and likewise has slidable and sealing contact with the sleeve 4. IIo this end, piston rings 8 are interposed'between the ram case and the sleeve. The. lower end of the ram case is sealed by a plug, 9, which is welded into the ram -case pressure tight. Mounted on the lowerend through which the plug 8 and the lower end of the ram case may be passed in securing the tramper foot onto the ram case. Welded between the two channel irons I I are two spreaders,

' I3, which are placedso as to hold snugly between them the bottom plug 9, which is held by a pin, 9, passing through the two spreaders I3. j

The tramper proper is supported by the sills, I4, which are in this case channel irons. At one end the sills are bolted at the bottom to a vertical channel iron, I4, which is bolted at the bottom to the press sills, which are in turn bolted to the concrete press foundation. 'I'he other ends of the tramper sills are bolted to the center column of the press (not shown). 'I'his is usually a square or rour'id steel column upon which the double box press revolves. The bottom of the center post or column is also bolted to the press sills, mentioned above. In its reciprocation, the ram case 1 is guided and kept aligned by a guide, I5, which is in turn held to the sills I4 by at plates, I8 and I1, bolted to said sills.

The casting 2, at the upper end of theftramper, and into which the upper end of the piston-rod is screwed, is held rigidly by the tension angles, I8, (Figs. 1 and 2), which in turn are bolted at their lower ends to the sills I4 through plate I6. rI'he piston-rod I must, of course, withstand the reaction from the ram case, due to the force'exerted in packing the cottohand also due to the down- To prevent leakage of the ram case 1 and piston-rod I, there is provided on the ram case a packing gland consistingof the parts indicated by the numerals, I8, 20 and 2I, of conventional Iand the wall of the ram case 1.

construction and arrangement, the part 2l being Y through discharge pipe, 23, (Figs. 1, 3 and 1),

which extends downward through piston-rod; I to the piston 3, into the top of which it is screwed. To prevent leakage of high pressure oil where pipe 23 passes through the top of casting 2, a packing gland, 24, is provided. i

Slidably mounted on piston 3 above the sleeve 4 is a ring, 25, (Figs. 1, 3, 5 and '7). Screwed flush by the stuffing box 20 against the top of the ram case -1 is a sleeve, 26. The sleeve 4 acts as a. valve to automatically change the ilow o! oil at each end of -the stroke of the ram case so as to reverse its direction and keep it going continuously. In the downward movement of the ram case the sleeve 26 will engage the ring 25 which will in turn engage the top o f sleeve 4 to move the sleeve downward. The ring 25 merely acts as an auxiliary plunger, in connection witl sleeve 28, this arrangement being provided in order to prevent the necessity of having ram case 1 move down so far that the packing 2| would be cut by the joint between piston rod I and piston 3. In each downward movement of the ram case the.sleeve"26 operates to push sleeve 4 down to its extreme lowermost position.

In its extreme lowermost position sleeve 4 will have opened an outlet to the lower inside of the ram case, which relieves the pressure therein, allowing the high pressure oil being pumped into the upper chamber to raise the ram case. As soon as the ram case reaches its uppermost position, the bottom plug Ill will have engaged sleeve 4 and shifted it back to its extreme uppermost position,-in which position it will have closed the outlet to the lower chamber and opened a passage for the high pressure oil to be pumped into the lower chamber. At the same time, this same passage will allow the oil in the upper chamber to also iiow into the lower chamber. Hence, the cycle of operation is completed and the tramper starts down on the next cycle. The arrangement of parts by means of which the foregoingoperation of the tramper is'eiected by the inletot pressure oil to the piston will now be described,

vreferringuto Figures 3 to 11 inclusive of the drawings.

In its upper portion, the'pi'ston 3 is provided with a hollow portion, or chamber, 21, '(Flgs. 3,

5 and 7), the wall of which is'provided on opposite sides with ports, 28, 29 anden, 3l, separated equal distances from each other.l 'I'he sleeve 4, in portion thereof occupied by the piston rings 8, divides the ram case 1 into an upper chamber 32 (Fig. 1) and a lower chamber 33 (Fig. 3) and the ports 29-3I communicate with the upper chamber 32 above the level of the top of sleeve 4 when the latter is in its uppermost position, as shown by Figs. 3,5 and '7.

The sleeve '4 in its lower portion, that is in the part 4*i thereof below the bearing portion containing the piston rings 8, is reduced in diameter to provide an annular space 34 between its wall lower end of this reduced prtion the wall of the sleeve is-provided with a port 35, which is located at such distance above the bottom 5 as to be moved beyond the lower end of the piston 3 when the sleeve is moved to its extreme lower position tul Toward the so as to open commimication between the lower 75 'the outlet passage31, in a manner to form a continuation of said passage (Figures 3 and "7). At the bottom of the outlet passage 31 the wall of said passage and the body of the piston is cut through to provide an enlarged or circumferential port, 38, (Figures 3, 4 and 7) which, when the sleeve is in its lowermost position (Figures 9 to 1l) registers with a circumferential series of ports,.39, formed in the wall of the reduced portion la of sleeve -4 at the upper end thereof.

When the ports 38 and 39 are in register they establish communication from the lower chamber 33 of the ram case through the annular passage 34 to the outlet passage 31.

To provide for the passage to the lower chamber 33 of the ram case of pressure oil passing through the hollow piston rod i to the chamber 21 of the piston, the latter is' provided-with an inlet passage, 40,'extending longitudinally through the piston from the bottom of chamber 21 to near the bottom of the piston where a port, 4|, is provided leading from the bottom of inlet passage 48 to the outer side of the piston (Figures 5, 7, 10 and 11). When the sleeve is in its uppermost position, as shown by Figure 7, the port 4| of the piston is in register with the port 35 of the sleeve 4, previously referred to, which permits the pressure oil to pass directly from the chamber 21.

through passage 40, ports 4| and 35, and annular passage 34 to the lower chamber 33 of the ram Case.

In order to control the application of the pressure oil effective within the chamber 36 ofthe sleeve, to permit, or prevent, the movement of said sleeve in the downward or'upward movement of the ram case, so Vthat said sleeve may function drical bore, 40a, l(Figures 4 and 12) in which is slidably mounted a plunger-valve, indicated generally by the numeral 4|a (Figures'B, 5, 9 and 10) This plunger-valve comprises, preferably as an integral structure, a plunger-rod, 42, having at its lower end a plunger-valve, 43; below said valve a reduced portion, 44, and at the lower end of the portion 44 a small foot-valve, 45. The valves 43--45 divide the bore 4i!a into an upper valvechamber, 46,' (Figures 9 and 10) and the lower valve chamber, 41, (Figures 3 and 5). Between the valves 43 and 45 the reduced portion 44 provides an annular intermediate Valve-chamber, 48. The lower end of bore 4| is closed by a screw-plug, 49. A small longitudinal bore, 50, extending through Valve 43 from end to end thereof serves to afford communicationbetween the intermediate valve-chamber 48 and the upper valvechamber 46 for a purpose to be presently described. The piston 3 is further provided with y 5I to the sleeve chamber .36, thus balancing the pressure on both sides of the sleeve.

' chamber 48, whereby communication from sleeve chamber 36 through hole 5I and ports 52 with the intermediate valve chamber 48 may be established. From the intermediate valve chamber 48 ports, 53, (Figs. 3, 4, 6 and 7) communicate with the outlet passage 31. Leading from the lower valve chamber 41 are ports, 54, which extend through the wall of said chamber (Figures 3, v6 and 9) and which, when the sleeve 4 is in its 10 uppermost position, as shown in Figure 3, are

in communication with ports, 55, extending through the wall of the sleeve wherebycommunication vmay be established between the annular space 34 andl said ports with the lower valve 15 chamber 41. When the plunger valve 4I has been lowered, as hereinafter'described, the ports- 54 and 55 will be placed in communication with the intermediate valve-chamber 48 and hence with ports 52, which movement 'of the plunger valve occurs prior to the downward movement of sleeve 4, `so that pressure oil from the lower ram case chamber 33 may passthrough annular space-34 ports 55, 54 and 52 through cored hole v25 Hence, no resistance will be offered to the subsequent downward movement of said sleeve..

In order to maintain the plunger valve 4Ia in its upward position prior to the time it is moved downward by contact of sleeve 26 at the upper end of the ram case 1 with the slide ring 25, which in turn is adapted to engage the plunger rod 42, the small port 56 is provided which permits high pressure oil i'rom the inlet passage 40 to enter 35 valve 'chamber 41 and thus exert upward pressure on the bottom of the plunger valve. (See Figures 5 and 10.)

The portion of the piston 3 above the bearing portionA thereof provided with the piston rings 6 is 40 reduced in diameter and on this reduced portion is slidably mounted the ring 25, previously referred to. This ring .is uted on the outside to provide ports, 51, (Figures 3 and 8) to allow free passage of oil on the downward stroke of the ram case from the upper chamber 32 to ports 28 and into the hollow port 21 of piste-n 3. Mounted in a circular groove provided in the interior' wall of sleeve 4 at itsupper end is a stop ring, 58. (Figure 3), vwhich also is .adapted to slide upon the said reduced portion of the piston. This reduced portion provides a circular shoulder, 59, which will Serve to limit the downward movement of 'sleeve 4 when engaged by the stop ring 58.

In order to cushion the sleeve 4 at the extreme limit'of its downward movement, in case the tramper should be operated without packing cotton, I provide a port, 60, best shown in Figures 7 and 8, which port is relatively wide at its upper end, and tapers to a mere slit at its lower end. 60

This port is provided in the wall of the inlet passage 40 and hence oil may pass through said port to the annular space, 6|, surrounding the reduced portion of the piston and closed at its upper end by stop ring 58. 4As thesleeve 4 is moved 65 downward, the gradually decreasing area of port 68 offers increasing resistance to the expulsion of oil through said port by stop ring 58 and causes the movement of the sleeve to be slowed down. 'I'he operation of the tramper will now be described, iirst premising that Figures 1, 3, 5 and '7, and the-sectional views, Figures 4, 6 and 8, illustrate the position of parts when the ram case 1, sleeve 4 and plunger valve 4I are in their uppermost position; while Figures 9, 10, 11 and 12 illusrod i into piston chamber 21, through inlet passage 43, out of port 4| in piston, through registering port 35 in sleeve 4, along annular passage 3l between ram case 1 and said sleeve, and into lower chamber 33 of the ram case. At the same time, oil, under the same pressure, is flowing out of the upper chamber 32 of the ram case through ports .23 and 30 into piston chamber 21 and In the same manner as described -to the lower chamber 33 of the ram case. Since on the downward stroke the high pressure oil is exerting pressure in both the upper and lower chambers of .the ramcase, the force in the lower chamber tending tov push the ram case 1 down, and the force in the upper chamber tending tp push it up, it will be seen that the net force available for packing the cotton will be'equal to the difference between the areas which are filled with oil in the upper and lower-chambers. In other words, the force push- ,the tramper will exert is equal to the area of the piston-md times the pressure developed by the pump.

On the downward stroke there are no outlets open. 'I'his feature of the invention reduces the quantity of oil needed 'to operate the tramper. The amount of oil required to drive the tramper down is equal to the area of the piston-rod multiplied by the length of the stroke.

The plunger valve is held in its upper position by high pressure oil passing through the small port to valve chamber 41 from the inlet port 43. At the same time pressure oil passes from the lower .chamber 33 of the ram case through annular space 3 4 and ports 55, 54 to said valve chamber. The intermediate valve chamber 43 is in communication with the cored hole 5I in the piston through ports 52 and with the outlet 31 through ports 53. Chamber 35 in the lower end of the lower chamber 35 of sleeve 2.

'I'he upper plunger 4chamber 43 has zero pressure since it communicates through port 53 in valve 43 with the intermediatevalve chamber 45, which is in communication with outlet 31 through A ports 53. Y

. While pump pressure acts on the upper end of the plunger rod 42 inV piston chamber 21, since the area of this plunger rod is less than that of valve 43, there will be a net force tol hold valve 3 in its upper position.'

As the ram case 1 moves downward under the pressureof oil in its lower chamber 33, the rst event occurs whensieeve 24 (Figure l) engages ring 25 which'in turn engages plunger rod 42 to move the` plunger valve 4I' downward. To facilitateithls operation I preferably'f-securea bar, 52, (Figure 3) -to the upper end of thepres'sure rod by means of a bolt, 63. 'I'his bar extends clear through the wam of piston chamber 21 into ang 25 to which it is secured (Figure 8). The walls of chamber 21 `are slotted to allow the bar 52 to move up and down,.fonel of these slots being shown by full lines in Figure 9 and indicated by the numeral 54. Bar 62 will therefore be engaged at opposite ends by ring 25 as the latter is moved downward, as will be apparent fromv inspection of Figure 8. As the plunger valve moves down, the valve 43 will cover ports 53 before ring 25 has moved down far enough to engage sleeve 4, and foot-valve 45 will ilrst cover and then uncover ports`54 to place them in communication with the intermediate valve-chamber 43 and ports 52. At this stage, i. e., with the plunger-valve lowered to substantially the position shown in Figure 9, but with sleeve 4 in the raised position in Figure 3, the high pressure oil in lower chamber 33 is in communication with the sleeve chamber 36 by means of vannular space 34, ports 55v and 54, intermediate. valve chamber 43, ports 52 and the cored hole 5i. Therefore, the pressure inside chamber 36 is the same as outside and sleeve 4 will offer no resistance to beingpushed down. The ring 25 now engages the upper end of sleeve 4 and pushes the sleeve down moving port 35 beyond port, 4l of inlet passage 40, thereby closing port 4| and cutting ofi-passage of pressure oil to the lower chamber 33 of the ram case. The pressure on the lower end of sleeve 4, both inside and out, ls now the same as at the upper end, and the sleeve is therefore floating, therefore only a slight force is required to move it down, which is only the amount of force required to overcome a small frictional resistance. Also, except for the small force needed at first to hold down plunger-valve 41 as explained later on, the same force is available for packing cotton as was available at the beginning of the downward -stroke, namely, the oil pressure times the area of piston rod i.

The oil is now flowing only into upper chamber 32, and no outlets are open. Therefore. this oil will move sleeve 4 down until port 35 in sleeve 4 opens into chamber 35, Figure 9, which affords. another means of allowing the oil in chamber 33 of the ram case and chamber 36 of sleeve 4,

to communicate. In this movement of the sleeve port 55 will be moved beyond port 54, closing the latter. -The downward movement of sleeve 4 just described is permitted by the fact that the ram -case 1 moves downward simultaneously with the sleeve, but at a slower rate, increasing the length of chamber. to provide space for the oil displaced by the downward travel of the sleeve. Thusas stated, the sleeve is floating, since on its upper Vend, chamber 21 and ports 51;/tinside its lower end, chamber 35; and outside its lower end, chamber 33, all pressures are the same, and equal to the pump pressure, disregarding a slightly greater pressure inthe upper chamber 21 due to v the frictional resistance offered to movement by the sleeve. The latter is' now free to move down because there is no fluid pressure or mechanical obstruction holding it up. At this point the'sleeve is merely a floating connection between the fluid in the upper and lower portions, 32 and 33, re-

spectively, of the ram case. The oil pressure in the lower chamber is acting over the entire area of the inside of the ram case, while in the upper chamber the same pressure is acting only over the area of the inside of thev4 ram case, less the area of the piston rod. Therefore, as before, the net force exerted by the ram is equal to the pump pressure times the difference between the area in the lower and upper chambers, which area is equal to the area of the piston rod. If, now, it be assumed that sleeve 4 does not move downward at this point, then the oil being pumped into the upper chamber 32 through hollow piston rod I,A

will immediately increase in pressure and act on the upper annular end of the sleeve, forcing the sleevedown against the oil in lower chamber 33 of the ram case. This will cause the pressure in this chamber to rise equally (or nearlyso) in amount to the rise of pressure in the upper chamber. However, the oil in the lower chamber 33 acts downward on the endof the ram case 1 on an area much'larger than the annular area of chamber 32 of the upper end of the ram case. Therefore,'the ram case will have a greater increase in force downward and will travel downward, increasing the'area of lower chamber 33, allowing sleeve 4 to slide downward. Finally, ports 39 in sleeve 4, (Figure 12), are moved into register with port 38 in piston 3 to relieve pressure in chamber V33 by providing an outlet through annular passage 34, ports 33 and 38 and outlet passage 31.

At this point, pressure both inside and outside of sleeve 4, including chamber 33 of the ram case and chamber 36 of the sleeve has been reduced to zero, and the sleeve has 4reached its lowermost pull the sleeve down. This is best explained by of oil into the lower chamber 33.

it down' further'.

position. The oil pressure in the upper ram case, chamber 32 will hold sleeve 4 down in this position and force the ram case to proceed upward, the oil in the lower chamber 33 being discharged.

At this point, it may be desirable to explain what holds the sleeve 4 in its uppermost position for substantially the duration of the downward stroke of the ram case, since in both upper chamber 32 and lower chamber 33 the pressures are equal and the friction of the ram case tends to assuming that sleeve 4 doesA slip down closing ports 4| and 35, and cutting oil' the admission Now, as pressure oil is still being pumped, the immediate effect will. be a sudden rise of pressure in the upper chamber 32. This rise in pressure 4in the upper chamber, when considered alone, will act against the area of sleeve 4tending to push However, this pressure also acts against the top area 'of the upper chamber 32. .This will naturally tend .to force the ram case up` The effect of this will raise the pressure of the oil in the lower chamber 33. Of course, it will not raise it n'early as high as the pressure in the upper chamber. Now, chamber 36 of the sleeve has zero pressure in it'and as the area;

is equal to the area of the piston 3, the slight 'increase of oil pressure in the lower chamber 32 acts over a largearea, unopposed by pressure from the other side. Always to be considered is the fact that the oil in chamber33 acts against the area of the sleeve as well as that area equal to the piston area. tioned that the' pressure increase in the lower chamber, (due to the Iincrease of pressure in the upper chamber acting upon the top of the ram case) tending to push the sleeve up againstvthe entire area of the inside of the ram case, of which area an amountof area, equal to the piston area, has no pressure at all acting on the other side, pushes up on the sleeve with 'a greater force than the force in the upper chamber pushes down. The result is that the sleeve can not slip down fras soon as it closes ports 35 and 4| slightly, a rise in pressure pushes it back.

I have heretofore referred to the small force lthe tramper would otherwise exert.

Theareas are so proporneeded at first to hold the plunger valve down as the ram case approaches the limit of its downward movement. An explanation of this will now be given.

At the completion of the downward stroke, the first event occurs when the plunger-valve closes ports 53, thereby closing the outlet from sleeve,

chamber 36. This requires a certain amount of lforce, which will have to be deducted from the force the tramper will exert for packing cotton. However, as soon as ports 53 are closed and ports 54 begin to open, no force will be required to push the plunger-valve for the remainder of the downward stroke. 'I'he reason for this is that as soon as portsl 53- are closed and ports 54 begin to open, the oil .pressure in the intermediate valve chamber 48 will be the same as the pressure in the lower valvechamber 41, and through the port 50 in valve 43 the upper valve chamber 46 will also have the same pressure.

Since the pressure acting against the top of plunger-rod 42I is equal tothe same pressure as in valve chambers 46 and 41, all pressure will be the same and no force will be required to hold or push down the plunger valve. l

Notwithstanding the above, one is not justified, actually, in deducting the force required for pushing down the plunger-valve from that force In packing cotton, the last few inches of movement of the tramper require very great increase in force, Now at the time the force required to push down the plunger-valve is neutralized, the tramper is still over an inch from the end of the stroke. To this point to the end of the stroke, the rise in force required to pack the cotton greatly exceeds the force that was required bythe plunger-valve. This is only to say that if a maxsmall amount required for theV plunger-valve for the duration of about one inch, when the tramper is still within several inches of the end of the stroke, will not lessen the packingl power of the tramper. It is also obvious that the only force necessary to overcome in pushing down the plunger-valve, is that force designed to push the plunger valve up against the resistance of gravity and friction.

As soon as the ram case starts upward the high pressure oil communicating from cored inlet hole 40 through small port 56 to lower valve chamber 41 will force the plunger-valve back into its uppermost position, or that shown in Figure 3. Since ports 54 and 55 are closed at this time, this high pressure. oil cannot run out of chamber 41 into the annular space 34 to the lower chamber 33 and be wasted to the outlet. -This is the4 reason ports 54 and 55 need to be closed. i

ports 54A and 55 will open before port 35 in sleeve 4 closes communication with chamber 36, which is connected to the outlet. Therefore, there will occur a momentary leakage of oil from inlet passage 40 through port 56 to chamber 41, through ports 54 and 55, annular space 34, port 35 to chamber 36, out through the cored hole 5|, ports 52 intermediate valve chamber 48, ports 53, to

outlet 31.

This leakage will only be momentary as the sleeve l is moving up rapidly at this point. Also rport 56 is so small thatin the time available no top of the ram case is of larger area than that of the sleeve, as is obvious from an inspection o f the drawings. Accordingly, if the oil acts upward on a larger area of the ram case than it acts down on the sleeve, the ram case will raise the sleeve, due allowance having been made for the weight of the ram case. As the sleeve rises, it will close outlet ports 38 and 39 and port 35 in said sleeve, which allowed lower chamber another outlet through annular space 34 into sleeve chamber 36. The plunger valve is still maintaining an outlet from this chamber', as explained above. Since the outlet to the lower chamber Il is closed, and since the oil is being pumped into the upper chamber 32 against the upper area of the ram case, the oil pressure in the lower chamber 33 will build up, andwlth no pressure inside the sleeve, the latter will move to its uppermost position, as has previously been explained in describing the manner in which the sleeve was held up during the downward movement of the ram case.

. After the sleeve and ram case have been raised, in the manner just described, the parts will then be in the position as shown in Figure 3 and the downward movement of the ram case under the pressure of oil will be repeated in' the manner which has been described.

From the foregoing it will beiseen that I have provided an exceedingly simple construction of tramper having, as stated, only three moving parts, and as these parts are constantly lubricated by the oil pumped into the tramper in the operation thereof, there is practically no wear due to friction, and as the moving parts are not mechanically connected, there is no part of the tramper which is liable to get out of order. At the same time, the efficiency 'of the device is very great, and due to the fact that the oil in the upper chamber discharges into the lower chamber, in

stead of to the outlet, the amount of oil required to be pumped to operate the tramper isl reduced to the minimum.

I claim; 1.*A hydraulic motor for a tramper comprising, in combination, a stationary piston having an inlet and an outlet passage each of which is provided with a port. a sleeve slidably mounted 'on the piston having a closed bottom providing, with the bottom of the piston, a sleeve chamber, a ram case slidably mounted on the sleeve' and providing upper and lower pressure chambers, to the pressures in which said sleeve is responsive, the upper chamber having a less pressure area than the lower, an inlet and an outlet port in said sleeve ,co-operating ,with the corresponding ports in said piston for controlling the admission and discharge of pressure oil to and. from said lower chamber, a port in said piston affording communication between said inlet passage and the upper chamber of the ram case, whereby pressure oil admitted to lsaid inlet passage with the ram case andsleeve in their uppermost position will enter said lower y t pressure chamber and force the ram case downengage said sleeve and, supplemented by pressure in the upper chamber, move it downward to change the position of the ports so as to close the inlet tothe lower chamber and permit pressure oil to discharge therefrom, while pressure oil entering said upper chamber will thereafter raise said ram case and cause its lower end to engage and raise said sleeve to its uppermost position, and means operating automatically in the described movements oi the ram case and sleeve to cause the application of pressure within, or its removal from, said sleeve chamber, to permit the movements of the sleeve.

2. A hydraulic motor for a tramper comprising, in combination, a fixed, depending pistonrod having at its lower end an unitary piston provided with inlet and outlet passages each having ports, a sleeve of greater length than the piston slidably mounted thereon, having a closed bottom, and having ports adapted to cooperate, respectively, with ports of the piston, a ram case of greater length than the sleeve slidably mounted thereon, providing sealed upper and lower chambers, one port in said piston` affording communication between its inlet passage and theupper -'chamber of the ram case,said ram case being adapted at the end of its upward and downward movements to move said sleeve in a corresponding direction, and the latter being responsive to oil pressure in said chambers, the relative disposition oi' the ports beingsuch that with the ram and sleeve in their uppermost position oil under pressure admitted to said inlet passage will pass into said lower chamber and force the ram case downward,thereby causing said sleeve to be moved to l change the position of its ports to shut off thepassage of oil to said lower chamber and release the pressure oil therefrom, while pressure oil will enter said upper chamber and thereafter raise the ram case and cause-the latter to raise said sleeve, and means automatically operating in the described movements of the ram case and sleeve to control the application of pressure to, or its removalfrom, said sleeve, to permit the movements thereof.

3. A hydraulic motor for a tramper comprising, in combination, a fixed, depending piston-rod having at its lower end an unitary piston provided with inlet and outlet passages each having ports, a sleeve of greater length than the piston slidably mounted thereon, having a closed bottom, and having ports adapted to cooperate with ports of the piston, a ram case of greater length than the sleeve slidably mounted thereon, providing sealed upper and lower chambers, one port in said piston allording communication between its inlet passage and the upper chamber of the ram case, said ram case being adapted at the end of its upward and downward movements to move said sleeve in a corresponding direction, and the latter being responsive to oil pressure in said chambers, the relative disposition of the ports being such that with the ram case and sleeve in their uppermost position oil under pressure ad- `mitted to said inlet passage will pass into said lower chamber and force the ram case downward, thereby causing said sleeve to be moved to change the position of its ports to shut o! the passage of oil to said lower chamber and release 4the pressure oil therefrom, while pressure oil entering said upper chamber will thereafter raise the ram case and cause the latter to raise said sleeve, and av plunger valve automatically .operating in the de scribed movements of the case and sleeve to ward to cause the upper end of the ram case to- Control the pplicatiOOf l'eISule'tO. 0r its re- 76 moval from, said sleeve, to governthe movements thereof.

4. A hydraulic motor fo. 'a tramper comprising, in combination, a xed, depending piston-rod, a stationary piston secured on the lower end thereof, having an inlet and an outlet passage provided, respectively, with an inlet and an outlet port, a sleeve slidably mounted on said piston having a closed bottom, a ram case of greater length than the sleeve slidably mounted thereon and providing upper and lower sealed chambers. the upper chamber having a less pressure area than the lower chamber and being in constant communication with said inlet passage, said sleeve ,having portscontrolling communication of said inlet and outlet ports with said lower chamber and being itself responsive to pressures in both of said chambers, the relative disposition of the ports being such that, with the ram case and sleeve in their uppermost position, `pressure oil admitted into said inlet passage will pass into said lo'ver chamber and force the ram case downward. causing its upper end to move the sleeve downward to close said inlet port while pressure in the upper chamber will complete the downward movement of the sleeve to open said outlet port, and will thereafter raise the ram case and cause its bottom to raise said sleeve, and meansoperating automatically in the downward movement of the ram case to balancepressures above and below the bottom of the sleeve to permit of its downward movement, and thereafter to release the pressure above said bottom to permit of the upward movement of the sleeve.

5. A hydraulic motor for a tramper comprising, in combination, a fixed, vdepending piston-rod having at its lower end an unitary piston provided with inlet and outlet passages each having a port, a iioating sleeve of greater length than the piston slidably mounted thereon, having a closed bottom providing between itself and the bottom of the piston a sleeve chamber, and having ports adapted to cooperate, respectively,`with the ports of the piston, a ram case of greater length than the sleeve slidably mounted thereon and providing sealed upper and lower chambers, a port in said piston affording communication between its inlet passage and saidupper chamber, a valve chamber in the piston, a plunger valve mounted therein normally subject on its lower end to pres-v ward to close the outlet port in the valve chamberl and admit pressure ioil from said lower chamber through the valve chamber into said sleeve chaml ber, and then move said sleeve downward to close the inlet to the lower chamber, pressure in the upper chamber will next i'orce the sleeve still lower `to open the portto said outlet passage, and thereafter raise theram case, and the plunger valve will belraised by oil pressure to permit oil from the sleeve chamber to pass through the valve chamber to said'outlet passage.

6. A hydraulic motor for a tramper comprising,

1 in combination, a fixed, depending piston-rodl having at its lower end a piston provided with inlet and outlet passages each having ports, a sleeve slidably mounted on the piston having a closed bottom, and having ports adapted to cooperate, respectively, with ports of the piston, a ram case slidably mounted on the sleeve providing upper and lower sealed chambers, one port in said piston alording communication between its inlet passage and said upper chamber, said ram case being adapted at the end of its upward and downward movements to move said sleeve in a corresponding direction, and the latter being responsive to oil pressures in said chambers, the relative disposition of the ports being such that with the ram case and sleeve in their uppermost position, oil under pressure admitted to said inlet pasthe ram case downward, thereby causing said sleeve to be moved to change the position of its ports to shut oi the passage of oil to said lower chamber and release the pressure oil therefrom, while pressure oil entering said upper chamber will thereafter raise the ram case and cause the latter to raise said sleeve, and a plunger valve subject on its under side to oil pressure from said inlet passage and adapted to be lowered by said ram case in the downward movement thereof, and to be raised by oil pressure in theupward movement of the yram case, and ports controlled by said plunger valve, whereby, in the described movements of the ram case and sleeve, said plunger valve will control the application of pressure to,

`or its removal from, saidsleeve to permit the movements thereof.

'7. A hydraulic motor for a tramper comprising, incombination, a fixed, depending rod having at its lower end a pistony provided with inlet and outlet passages each having a port, a sleeve slidably mounted on the piston having a closed bottom', and having inlet and outlet ports adapted to cooperate, respectively, with the inlet and outlet ports of the piston, a ram case of greater length than the sleeve slidably mounted thereon pro-l 4 sage will pass into said lower chamber and force viding sealed upper and lower chambers, the

upper chamber having a less pressure area than i the lower and being in constant communication with said inlet passage, said ram case being adapted at the end of its upward and downward movements to move said sleeve in a corresponding direction, and the latter being responsive to oil pressures in Asaid chambers, the relative disposition of the ports being such that with the ram case and sleeve in their uppermost position, oil under pressure admitted to said inlet passage will pass into said lower chamber and force the ram case downward,athereby causing said sleeve to be moved to change the position of its ports to shut off the passage of oil to saidv lower chamber and release the pressure oil therefrom, while pressure oil will enter said upper chamber to thereafter raise theram case andcause the latter to raise said sleeve, and a plunger valve normally responsive on its under side to oil pressure and adapted to be lowered by said ram case in the downward movement thereof prior to the downward movement oi? said sleeve and to be raised by oil pressure in the upward movement of the ram case prior to the upwardl movement of the sleeve, said plunger valve operating in its movements to control the application of pressure to, or its removal from, said sleeve, to permit the movements thereof.

8. A hydraulic motor for a tramper comprising, in combination, ajlxed, depending piston-rod having at its lower end' an unitary piston provided with inlet and outlet passages each having a port, a sleeve o! greater length than the piston slidably mounted thereon having a lower closed end providing a chamber between itself and the lower end of the piston and having upper and lower ports adapted to cooperate with the inlet and outlet ports of the piston, respectively, a ram case of greater length than the sleeve slidably mounted thereon, providing sealed chambers above and below the sleeve, one port in said piston affording constant communicationbetween its inlet passage and s aid upper chamber; said ram case being adapted at the end of its upward and. downward movements to move said sleeve in a corresponding direction, and the latter being responsive'to oil pressure in said chambers, the relative disposition of the ports and pressure areas of said upper and lower chambers being such that, with the ram case and sleeve in their uppermost position, oil unde'r pressure admitted to said inlet passage will pass into the lower chamber of the ram case and force it downward, thereby causing said sleeve to change the position of its ports to close .the inlet to said lower chamber while the pressure in said upper chamber will complete the downward movement of the sleeve to open the port to said outlet passage,

and move said lower sleeve port beyond the end of the piston to permit the pressure oil in the lower chamber oi the ram case to pass through said port into said sleeve chamber, and thereafter raise the-ram case, and a plunger valveoperating automatically in the described movements of the parts to place said sleeve chamber in communication with said outlet passage to permit the escape of oil from said sleeve chamber as the sleeve is raised.

9. A lhydraulic motor for a tramper comprising, in combination, a fixed depending pistonrod having at its lower end an unitary piston provided with inlet and outlet passages each having a port, a sleeve of greater length than the piston slidably mounted thereon, having a lower closed end providing a chamber between itself and the lower end of the piston, the pressures inside and outside oi' which are initially equalized, and 'having an inlet and outlet port,` adapted to cooperate with the inlet and outlet ports of the piston, a ram case of greater length than the sleeve slidably mounted thereon, providing upper and lower sealed chambers, the lower chamber having a greater pressure area than the upper chamber, and the latter chamber being in constant communication with said inlet passage, said ram case being adapted at the end of its upward -ond downward movements to move said sleeve in a corresponding direction, the relative disposition oi' the ports being such that with the ram case and sleeve in their uppermost position oil under pressure admitted to said inlet 4passage will pass into the upper and lower chambers oi.' the ram case and, due to the greater area of the latter chamber, move the am case downward, forcing the oil in the upper chamber to now .into said lower chamber and, toward the termination of its downward stroke, move said sleeve to change the position o! the ports to close the inlet to said lower chamber and permit oil pressure in the upper chamber to move said sleeve still lower to open said outlet port and move said inlet port beyond the end of the piston to permit the pressure oil in the lower chamber of the'ram case to pass through said portv into said sleeve chamber, and a plunger valve operating automatically in the downward movement of the ram case to admit pressure oil to said sleeve chamber 'and in the upward stroke of the ram case to place said sleeve chamber in communication with said outlet passage to permit the escape of oil from said sleeve chamber as the sleeve is raised by the ram case.

10. A hydraulic motor for a .tramper comprising, in combination, a iixed, depending piston-rodmounted thereon having4 a lower closed end providing a chamber between itself and the lower end of the piston and having an upper outlet and a lower inlet port adapted to cooperate with corresponding ports of the piston, a ram case of greater length than the sleeve slidably -mounted thereon, providing upper and lower sealed chambers and adapted at the end of its upward and downward movements to move said sleeve in a corresponding `direction, and the latter being responsive to oil pressure in said chambers, a. valve chamber provided in said piston and having a port in constant communication with said sleeve chamber, an outlet port, and an inlet port extending through the wall loi? said chamber, a port in said sleeve in constant communication with the lower chamber of the ram case and resistering with said inlet port of the valve chamber when the sleeve is in its uppermost position, and a plunger valve slidably mounted in said valve chamber normally subject to oil pressure on its lower end and adapted to be Iorceddownward by the ram case in the downward movement of the latter prior to the downward movement of the sleeve to close the outlet port of the valve chamber and admit pressure oil through said inlet port to the sleeve chamber and to said valve cham' ber above the valve, to balance pressures on said,

sleeve and valve, and to be moved upward by oil pressure in the upward movement o! the ram case, prior to the upward movement of the sleeve,

to permit pressure oil to escape from-said sleeve chamber through said outlet port.

11. A hydraulic motor for a tramper comprising, in combination, a ilxed, depending, hollow piston-rod having an inlet for pressure oil at its upper end, a piston secured on the lower end thereof having an inlet passage forming a continuation -of said piston-rod and an outlet passage, an outlet pipe extending through said hollow I piston-rod and of less diameter than the same and forming a continuation of said outlet passage, each of said passages having a port, a sleeve slidably mounted on the piston having a closed'bottom providing, with the bottom of the piston, a

portin said sleeve cooperating with the corre spending ports in said inlet and outlet es for controlling the admission and discharge 'of pressure oil to and from said lower chamber,

whereby, with the ram case and slee/ve in their uppermost position, pressure oil from said inlet will pass to said lowerA chamber and force the ram case downward to cause the upper end theneof to engage said sleeve and, supplemented by pressure in the upper chamber, move it downward 7| to change the position of the ports so as to close the inlet to the lower chamber and permit pressure oil to discharge therefrom, while pressure oil entering said upper chamber` will thereafter raise the ram case and cause its klower end to engage and raise said sleeve to its uppermost position, and means operating automatically in the described movements of the ram case and sleeve to v cause the application of pressure within, or its removal from. said sleeve chamber, to permitthe movements of the sleeve.

'12. A hydraulic motor for a tramper comprising, in combination, a ilxed, depending piston-rod having at its lower end a stationary piston provided with inlet and outlet passages, each having a port, a sleeve slidably mounted on the piston. having a closed bottom, and having ports adapted to cooperate, respectively, with the ports in the piston, a ram case of greater length than the sleeve slidably mounted thereon providing sealed chambers above and below the sleeve, the lower chamber having a greater pressure area than the upper chamber, and adapted at theend of its downward and upward movements'to Jmove said sleeve in a corresponding direction. a port in said piston l.

atiording 'constant communication between said inlet passage and the upper chamber of the ram case, and means for controlling the entrance oi pressure oil to and its escape from the sleeve chamber to govern the movements thereof, comprising a valve chamberin said piston having at .its lower end a small port communicating with to belowered in the downward movement of the ram case before the sleeve is lowered thereby. and to be raised by oil pressure in the upward movement of the ram case before said sleeve is moved upward thereby, said valve, in its movements controlling said outlet port. and passing over and beyond said fourth port in either direction.;

13. A hydraulic motor'acco'rding to claim 1, in which a portis provided between the inlet and said upper chamber which is reduced in area from itsupper to its lower end and a collar carried on the interior of said sleeve and slidable over said piston and port. whereby in the downward movement of the sleeve the same will be cushioned by the increasing resistance offered by the oil forced through said Dort.

DOUGLAS JonNs'roN. 

